Noble metal catalysts are commonly used for a variety of purposes in hydroprocessing environments. Examples of hydroprocessing using noble metal catalysts include, but are not limited to, hydrocracking processes, dewaxing processes, and aromatic saturation/hydrofinishing processes. The catalyst support material for supporting the noble metals can vary depending on the nature of the process.
One of the difficulties with using noble metal catalysts is maintaining the activity of the catalyst between the time of catalyst manufacture and the beginning of hydroprocessing. In particular, after manufacture of a noble metal catalyst, such a catalyst typically needs to be loaded into a reactor and then activated for use. Typical activation procedures can include a reducing step for converting metal oxides to a metal state with a lower oxidation number and/or a sulfiding step for preparing the metal sulfide that is typically considered the active form of a hydroprocessing catalyst.
U.S. Pat. No. 7,407,909 describes methods for ex-situ reduction and dry passivation of noble metal catalysts.